A flash smelting furnace is a smelting furnace used for a smelting of non-ferrous metal such as copper or nickel and a matte-treating smelting. The flash smelting furnace has a shaft in an upper portion of a settler of a reverberating furnace type. When raw material and reaction gas are blown from the top of the shaft, oxidizing heat of the raw material is used at a maximum. The raw material is instantly oxidized and melted. In the flash smelting furnace, an apparatus to supply the raw material and the reaction gas into a furnace acts as an important role to determine performance of the flash smelting furnace. The performance of the raw material supply apparatus determines reaction effectiveness and degree of reaction progress of the raw material in the reaction shaft. Thereby, the performance has influence on a processing capacity and metal recovery of the flash smelting furnace. It is preferable that the reaction in the reaction shaft of the flash smelting furnace is speedy and all raw material reacts evenly at an identical degree of reaction progress. It is therefore preferable that the raw material is supplied to the flash smelting furnace evenly.
Japanese Patent Application Publication No. 2003-160822 (hereinafter referred to as Document 1) discloses a technology in which raw material is supplied to a flash smelting furnace from three or more directions (for example, four directions) in order to evenly supply the raw material to the flash smelting furnace. Japanese Patent Application Publication No. 2013-513727 (hereinafter referred to as Document 2) discloses a technology in which a separation wall or a collision plate is provided in a supply passage of the raw material.